Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F9/00—Multistage treatment of water, waste water or sewage
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  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
  • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
  • C02F1/46104—Devices therefor; Their operating or servicing
  • C02F1/46109—Electrodes
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  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
  • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
  • C02F1/467—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction
  • C02F1/4672—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis by electrochemical disinfection; by electrooxydation or by electroreduction by electrooxydation
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  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/72—Treatment of water, waste water, or sewage by oxidation
  • C02F1/722—Oxidation by peroxides
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  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
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  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/28—Treatment of water, waste water, or sewage by sorption
  • C02F1/283—Treatment of water, waste water, or sewage by sorption using coal, charred products, or inorganic mixtures containing them
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  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
  • C02F1/444—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
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  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
  • C02F1/469—Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis
  • C02F1/4691—Capacitive deionisation
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  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/72—Treatment of water, waste water, or sewage by oxidation
  • C02F1/78—Treatment of water, waste water, or sewage by oxidation with ozone
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
  • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
  • C02F1/46104—Devices therefor; Their operating or servicing
  • C02F1/46109—Electrodes
  • C02F2001/46133—Electrodes characterised by the material
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  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
  • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
  • C02F1/46104—Devices therefor; Their operating or servicing
  • C02F1/46109—Electrodes
  • C02F2001/46152—Electrodes characterised by the shape or form
  • C02F2001/46157—Perforated or foraminous electrodes
  • C02F2001/46161—Porous electrodes
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2101/00—Nature of the contaminant
  • C02F2101/30—Organic compounds
  • C02F2101/301—Detergents, surfactants
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2101/00—Nature of the contaminant
  • C02F2101/30—Organic compounds
  • C02F2101/306—Pesticides
• • C—CHEMISTRY; METALLURGY
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  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2101/00—Nature of the contaminant
  • C02F2101/30—Organic compounds
  • C02F2101/36—Organic compounds containing halogen
  • C02F2101/363—PCB's; PCP's
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  • C02F2101/00—Nature of the contaminant
  • C02F2101/30—Organic compounds
  • C02F2101/38—Organic compounds containing nitrogen
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
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  • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
  • C02F2103/08—Seawater, e.g. for desalination
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
  • C02F2103/34—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32
  • C02F2103/343—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 from the pharmaceutical industry, e.g. containing antibiotics
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
  • C02F2103/34—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32
  • C02F2103/346—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 from semiconductor processing, e.g. waste water from polishing of wafers
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2201/00—Apparatus for treatment of water, waste water or sewage
  • C02F2201/46—Apparatus for electrochemical processes
  • C02F2201/461—Electrolysis apparatus
  • C02F2201/46105—Details relating to the electrolytic devices
  • C02F2201/4612—Controlling or monitoring
  • C02F2201/46125—Electrical variables
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2201/00—Apparatus for treatment of water, waste water or sewage
  • C02F2201/46—Apparatus for electrochemical processes
  • C02F2201/461—Electrolysis apparatus
  • C02F2201/46105—Details relating to the electrolytic devices
  • C02F2201/4616—Power supply
  • C02F2201/46165—Special power supply, e.g. solar energy or batteries
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2201/00—Apparatus for treatment of water, waste water or sewage
  • C02F2201/46—Apparatus for electrochemical processes
  • C02F2201/461—Electrolysis apparatus
  • C02F2201/46105—Details relating to the electrolytic devices
  • C02F2201/4619—Supplying gas to the electrolyte
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2201/00—Apparatus for treatment of water, waste water or sewage
  • C02F2201/78—Details relating to ozone treatment devices
  • C02F2201/782—Ozone generators
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/005—Processes using a programmable logic controller [PLC]
  • C02F2209/006—Processes using a programmable logic controller [PLC] comprising a software program or a logic diagram
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/005—Processes using a programmable logic controller [PLC]
  • C02F2209/008—Processes using a programmable logic controller [PLC] comprising telecommunication features, e.g. modems or antennas
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2209/00—Controlling or monitoring parameters in water treatment
  • C02F2209/40—Liquid flow rate
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2303/00—Specific treatment goals
  • C02F2303/04—Disinfection
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2303/00—Specific treatment goals
  • C02F2303/16—Regeneration of sorbents, filters
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2305/00—Use of specific compounds during water treatment
  • C02F2305/02—Specific form of oxidant
  • C02F2305/023—Reactive oxygen species, singlet oxygen, OH radical
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W10/00—Technologies for wastewater treatment
  • Y02W10/30—Wastewater or sewage treatment systems using renewable energies
  • Y02W10/37—Wastewater or sewage treatment systems using renewable energies using solar energy

Definitions

• the invention generally relates to water treatment, and more particularly, to water purification techniques that utilize electro-peroxone (e-peroxone) processes.
• e-peroxone electro-peroxone
• Filtration is a process whereby contaminants are physically removed by size exclusion.
• Known filtration processes include, for example, reverse osmosis and
• Drawbacks of filtration include clogging of the filter pores by contaminants, often resulting in fouling and frequent replacement of the filter. This may lead to high maintenance costs in some applications .
• AOPs Advanced oxidation processes include a number of different techniques, including ozonation, electrochemical oxidation, photo oxidation, peroxone (ozone/hydrogen peroxide) processes, electrical peroxone (or electro-peroxone )
• a drawback of these methods is the high cost of capital investment. For example, an electrode array used for electrochemical oxidation may cost over ten thousand dollars. Additionally, other drawbacks include oxidation processes that may be slow and energy intensive, and that are therefore often performed in batch reactors, by which purified effluent cannot be continuously discharged.
• Peroxone processes generally involve adding hydrogen peroxide into a batch reactor from an external source, whereas electro-peroxone processes generally involve the generation of hydrogen peroxide using a bonded carbon graphite cathode inside the batch reactor.
• electro-peroxone processes generally involve the generation of hydrogen peroxide using a bonded carbon graphite cathode inside the batch reactor.
• the use of a peroxone process may be impractical in some circumstances due to the high cost of hydrogen peroxide and the danger involved in its
• electro-peroxone processes may suffer from the rapid deterioration of the bonded carbon electrode due to the degradation of its binding agents
• An electrode may be used as a flow-through cathode in an electro-peroxone system providing vastly improved H 2 C>2 production activity for electrochemical water treatment.
• the electrode includes a porous carbon material synthesized from resorcinol.
• the electrode may be relatively inexpensive to manufacture and may allow a compact, highly efficient electrochemical water purification system with reduced energy consumption, reduced maintenance, lower cost, and wide application.
• the electrode may be used to remove pollutants from water and/or for desalination.
• the porous carbon material is a binding agent-free carbon structure that enables H 2 0 2 to be electro-generated in situ at electrode at a higher production rate.
• the electrode may be manufactured by dissolving resorcinol and a surfactant in a mixture of ethanol and water to form a solution. Base or acid is then added to the solution, and formaldehyde is added to the solution to form a solution mixture . The solution mixture is heated to produce a solidified material. The solidified material is dried, and pyrolysis is performed on the dried solidified material under a protective gas,
• the electrode can be used in systems that purify water by placing it in direct physical contact with the water and applying a suitable voltage potential.
• the disclosure also describes a water purification system including one or more electrodes comprising the porous carbon material synthesized from resorcinol.
• Figure 1 illustrates an exemplary water purification system including an electrode having porous carbon material, such as a continuous water purification system.
• Figure 2 is a schematic perspective view of an exemplary porous carbon electrode useable as a cathode in the system of Figure 1.
• Figure 3 illustrates the chemical reactions involved in an exemplary process of manufacturing porous carbon
• Figures 4a-d are scanning electron microscope images of examples of porous carbon materials.
• Figure 5 is conceptual perspective view showing example electrochemical operation of the anode and cathode of the system shown in Figure 1.
• Figure 6 is a schematic view showing an example modular water purification system including a disclosed porous carbon cathode.
• Figure 7 is an exploded perspective view of an exemplary ECR module included in the modular system shown in Figure 5.
• Figure 8a-c are graphs showing experimental results for CV curves for an example disclosed PCM electrode.
• Figure 9 is a graph showing experimental results of
• Figures lOa-f are graphs showing experimental results of pharmaceutical removal during wastewater treatment using an example disclosed porous carbon electrode.
• Figure 11 is a graph comparing the experimental results of wastewater treatment using an example disclosed porous carbon electrode and other water purification
• Figure 12 is a graph showing experimental results of desalination using an example disclosed porous carbon
• an inexpensive three-dimensional (3D) porous carbon electrode with large reactive surface area, large voidage, low tortuosity, and interconnected macropores are disclosed.
• the example electrodes can be applied in wastewater treatment systems as described herein.
• examples of a flow-through electro-peroxone water purification system in which H 2 C>2 may be electro-generated in situ by selective 0 2 reduction in a porous carbon material (PCM), are disclosed for efficient continuous removal of one or more contaminants, which
• contaminants may include pharmaceuticals, biological matter, biocides such as herbicides, pesticides and fungicides, human or animal waste, pathogenic contaminants such as viruses, bacteria or parasites, chemical pollutants such as PCBs, TCEs, phthalates, or the like, semiconductor manufacturing
• wastewater which may contain contaminants such as
• PFAS perfluoroalkylsulfonate surfactants
• TMAH tetramethylammonium hydroxide
• Figure 1 is a simplified illustration of an
• exemplary continuous water purification system 10 that includes a vessel 12 for holding an aqueous medium 20 such as wastewater, a first electrode (e.g., anode 14) and a second electrode (e.g., cathode 16) for use in water purification, and a voltage source 18 for providing current to the anode 14 and cathode 16.
• the system 10 can purify water having organic and/or inorganic matters by making use of one or more advanced oxidation processes (AOPs), such as an electro-peroxone process, to break contaminants, e.g. inorganic and/or organic matters, into small and stable molecules, such as water and C0 2 .
• AOPs advanced oxidation processes
• a pair of electrodes 14, 16 are illustrated, although additional electrodes 14, 16 can be employed.
• the system 10 illustrated in Figure 1 includes an inlet 22 and an outlet 24.
• the system 10 can operate as a continuous reactor in that the aqueous medium 20 flows into the vessel through the inlet 22, passes through the anode 14 and cathode 16, and out of the reservoir through the outlet 22. Both the anode 14 and cathode 16 may be porous to allow a liquid medium to pass through them.
• the system 10 can also be operated as a batch reactor, where the aqueous medium 20 does not continuously flow, but remains in the vessel 12 for a period of time in batches to be treated.
• the water purification system 10 can be used to purify wastewater or other fluids.
• Wastewater may include organic or biological matters that are normally associated with waste products and/or inorganic or chemical matters that are associated with industrial or manufacturing processes.
• the cathode 16 is composed of a porous carbon material (PCM) synthesized from resorcinol.
• the porous carbon material is a binding agent-free carbon structure that enables H 2 0 2 to be electro-generated in situ at the cathode 16 at a significantly higher production rate. This structure improves the performance of the cathode 16 and the system 10 in
• electrochemical wastewater treatment applications by providing a significantly more porous cathode with a relatively large reactive surface area, large voidage, low tortuosity, and interconnected macropores suitable for wastewater treatment.
• the anode 14 may be any suitable electrode for use in an electrochemical water treatment process.
• the anode 14 may be a titanium plate, having holes formed therein suitable for passing the aqueous medium 20 at a desired rate of flow.
• the perforated titanium plate may be coated with IrC>2.
• the anode 14 may be a metal plate, such as stainless steel or the like, or it may be a PCM electrode .
• the voltage source 18 may be any suitable means for supply current to the anode 14 and cathode 16 , such as a power supply, solar cell, and/or battery. During operation of the water purification system 10 , an anodic potential is applied by the source 18 between the anode 14 and the cathode 16 at a level that is sufficient to generate reactive species, e.g., hydrogen peroxide, at the cathode 16.
• reactive species e.g., hydrogen peroxide
• FIG 2 is a schematic perspective view of an example construction of the cathode 16.
• the cathode 16 is a schematic perspective view of an example construction of the cathode 16.
• the PCM 52 includes a porous carbon material (PCM) 52 and a conductor 54 contacting the bottom surface of the porous carbon material 52.
• the aqueous medium 20 flows through the porous carbon material 52 and conductor 54 during electrochemical processing of the influent water.
• the voltage source 18 supplies current to the cathode 16 by way of the conductor 54.
• the PCM 52 may be derived from carbonizing resorcinol formaldehyde polymer, as described below. The carbonization of the polymer may result in an absence of impurities in the PCM 52, i.e., a graphitic PCM 52.
• Figure 3 illustrates the chemical reactions involved in a general exemplary process of manufacturing the porous carbon material 52 included in a disclosed electrode.
• the chemical equations of Figure 3 describe the polymerization reaction involved in the formation of the base catalyzed porous resorcinol-formaldehyde (RF) polymer that makes up the PCM 52.
• RF porous resorcinol-formaldehyde
• the porous carbon material 52 of the cathode 16 may be synthesized by the following example process.
• resorcinol e.g., 3.0 g, 27.3 mmol
• a surfactant e.g., Pluronic® F-127 ⁇ e.g., 1.25 g
• ethanol e.g., 11.4 mL
• deionized water e.g., 9 mL
• the organic amine base 1 6-diaminohexane
• poly (benzoxazine-co-resol ) is then dried at room temperature or 90°C for 48 hours. Pyrolysis was performed at 800°C for two hours under a nitrogen gas protection (another inert gas and/or hydrogen gas can be used instead) .
• Different porous carbon materials may be prepared by using different reaction kinetics and processes. Using different reaction kinetics and/or processes may cause the resulting carbon materials to having different structures and properties, such as different porosities, different reactive surface areas, pore sizes, voidages, tortuosity, and
• Salt such as Na 2 CC>3 can also catalyze the reaction.
• the polymer may form even when no acid/base is added, but at a much slower rate.
• polymerization include but are not limited to: KOH, NaOH, Triethylamine , Ethylenediamine , Hexamethylenediamine ,
• PCM-X porous carbon materials
• EDA ethylenediamine
• DAH 6-Diaminohexane
• TMA trimethylamine
• TEA triethylamine
• Surfactants that may be used to create porosity inside the polymer include but are not limited to: all fluorinated surfactants, e.g., FC4430; all silicone based surfactants, cationic surfactants, and anionic surfactants such as CIOTAB, F-127 (CAS: 9003-11-6), SPAN80, and
• An advantage of the PCM 52 is the small footprint that it allows, which in turn reduces the physical size of a water purification system incorporating the PCM cathode 16 .
• the compactness of the PCM 52 allows multiple water purification systems to be carried by an individual person, and such systems may be conveniently connected to any existing installation or plumbing in extremely compact spaces .
• the compactness feature of the PCM cathode 16 is achieved by the relatively large reaction surface area of the porous carbon material 52 , which may be between 200-800 m 2 /g.
• porous carbon material 52 does not include any binding agent, the reactive surface area is increased with a reduction in energy loss during operation.
• the conductor 54 may be any suitable material for transferring electric current to the porous carbon material 52, and may act as an ohmic contact.
• the conductor 54 may be thin sheet or foil of metallic conductor having holes or passages formed therein for allowing fluid to flow through the conductor 54.
• the conductor 54 can be a porous material such as a mesh or fabric.
• Suitable materials for the conductor 54 include valve metals, such as Ti .
• cathode 16 may be
• the carbon material 52 and conductor may be formed into a rectangular or square shape or the like.
• Figures 4a-d are scanning electron microscope (SEM) images of example porous carbon materials.
• Figure 4a shows an image of the structure of a PCM prepared using
• Figure 4b shows an image of the structure of a PCM prepared using trimethylamine as the base in the polymer reaction.
• Figure 4c shows an image of the structure of a PCM prepared using ethylenediamine as the base in the polymer reaction.
• Figure 4d shows an image of the structure of a PCM prepared using potassium hydroxide as the base in the polymer reaction.
• Figure 4a structure formed using hexamethylenediamine
• Figure 4a has a more irregular porous structure, where increased defect sites enhance hydrogen peroxide production.
• the irregular porous structure of the PCM-HDA is retained after calcination at 800° C with nitrogen protection during the manufacturing process.
• At least some of pores of the PCM may have diameters of 1 ⁇ or more, for example, 5 ⁇ or more.
• PCMs having smaller pore sizes under 1 ⁇ may also be manufactured.
• FIG. 5 is conceptual perspective view 100 showing electrochemical operation of the anode 14 and cathode 16 of the continuous flow system 10 shown in Figure 1.
• the system includes the anode 14, the PCM cathode 16 (including porous carbon material 52 and conductor 54) , and a spacer 106 between the anode 14 and cathode 16 to prevent electrical contact between the anode 14 and cathode 16.
• the influent water 20 includes various contaminants
• the ozone 116 may be pumped into the influent water 20 by an ozone generator (e.g., as shown in Figure 6) .
• an ozone generator e.g., as shown in Figure 6
• the electrochemical action of the anode 14 splits some of the water molecules to generate 0 2 120.
• the water 20, including the remaining contaminants 114, ozone 116, oxygen 120 , and water molecules 118 then pass into the PCM 52 of the cathode 16 .
• the electro-peroxone process occurs, with certain oxidation reactions taking place. For example, oxygen is converted to 3 ⁇ 4(3 ⁇ 4 122 . The hydrogen peroxide may then become hydroxyl radicals 12 . The 3 ⁇ 4(3 ⁇ 4 122 may react with contaminates 114 to degrade them into oxidized byproducts 128 . Additionally, the ozone may oxidize contaminates into, for example, water 126 and CO 2 .
• Additional hydroxyl radicals may be
• Water soluble oxygen used by processes within the system may be supplied from two sources: 1) air-dissolved oxygen in the water influent that are not converted into ozone by an ozone generator; and 2) oxygen that are generated from water splitting at the anode 14, which is placed upstream of the cathode 16 inside the system 10.
• PCM cathode 16 Reduced maintenance is another advantage of the PCM cathode 16. Because both biofouling and chemical fouling occurring in PCM cathode 16 are constantly removed by advanced oxidation processes, the PCM 52 is therefore constantly regenerated and cleansed during use. Additionally, since neither the PCM cathode 16 nor the anode 14 directly
• Electrodes 14, 16 are much lesser prone to degradation, which is a common drawback in some known electrochemical water/wastewater treatment systems.
• FIG. 6 is a schematic view showing an example modular water purification system 200 including a porous carbon cathode, such as cathode 16 illustrated in Figures 1-4.
• the system 200 includes an outer shell 202 having an inlet 203 for admitting untreated water influent 201 and an outlet 205 for releasing treated water. Contained within the outer shell 202 is an activated carbon filter 204, an electrochemical reactor (ECR) 206, a polishing filter 208, an air pump 210, an ozone generator 212, a water pump 214, a control unit 211, and a power supply 216.
• ECR electrochemical reactor
• the modular system 200 is a continuous reactor that combines physical adsorption, electrochemical oxidation, and filtration processes in series to achieve improved water purification.
• Water 201 flows into the inlet 203 and, in turn, passes through each stage of the purification process.
• the first stage is the activated carbon filter 204, which may include granular activated carbon (GAC) , powered activated carbon (PAC), biochar, any suitable combination of the aforementioned, or the like.
• GAC granular activated carbon
• PAC powered activated carbon
• biochar any suitable combination of the aforementioned, or the like.
• the ECR 206 After the water passes through the activated carbon filter 204, it is received at the second stage, i.e., by the ECR 206, which performs one or more advanced oxidation processes (AOPs) involving the water.
• the ECR 206 may include the anode 14 and cathode 16 arranged as shown in Figures 1-4 to perform an electro-peroxone process involving the water.
• Ozone may be supplied to the ECR 206 by the ozone generator 212, which is supplied with air by the air pump 210.
• the third stage includes the polishing filter 208, which physically removes contaminants by size exclusion.
• the polishing filter 208 may include any suitable process or device for do this, such as a membrane, micro-filter, commercially-available micro-filter, any suitable combination of the foregoing, or the like.
• the water pump 214 may be any suitable device for moving incoming water through the stages of the system 200.
• the water pump 214 may be an electric centrifugal pump, positive displacement pump, peristaltic pump, or the like.
• the water pump 214 may be located elsewhere in the system 200 other than the location shown in Figure 6.
• the air pump 210 may be any suitable device for providing oxygen to the ozone generator 212, such as an air pump drawing air from the surrounding atmosphere.
• the air pump 210 may be an electric centrifugal pump, positive displacement pump, peristaltic pump, or the like.
• the air pump 210 may be located elsewhere in the system 200 other than the location shown in Figure 6.
• the ozone generator 212 may be a commercially- available ozone generator.
• the ozone generator may be a corona discharge ozone generator.
• the power supply 216 may be any suitable means for supplying electrical power to the control unit 211, air pump 210 and water pump 214, and supplying anodic current to the electrodes included in the ECR 206.
• the power supply 216 may include a regulator and one or more
• rechargeable batteries such as lithium or metal oxide batteries.
• the batteries may be recharged using a wall plug, or one or more solar panels.
• the power supply 216 may include an adapter for receiving electrical power directly from an external source, such as household outlets.
• the control unit 211 is any suitable means for controlling the operation of the system 200.
• the control unit 211 may control the voltage applied to the electrodes within the ECR 206 and the flow rate of both the air and water pumps, 210, 214. These operational parameters can be controlled to optimize the performance of the system 200 in terms of, for example, water purity or energy
• control unit 211 can tune the operation of the system 200, including the in situ hydrogen peroxide production of the PCM cathode in the ECR 206, by adjusting the parameters, for example, by adjusting the air pump flow to increase ozone generation and the anodic
• control unit 211 may be implemented in hardware, software, firmware, or any suitable combination thereof. If implemented in software, the
• Computer-readable media may include any computer-readable storage media, including data storage media, which may be any
• a computer program product may include a computer-readable medium.
• Computer-readable storage media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disc storage, magnetic disk storage, or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.
• Disk and disc includes compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk and blu-ray disc, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer- readable media .
• the control unit 211 may include one or more processors for executing instructions or code, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry.
• DSPs digital signal processors
• ASICs application specific integrated circuits
• FPGAs field programmable logic arrays
• the control unit 211 may also include memory.
• the memory and processor may be combined as a single chip.
• the control unit 211 may optionally include a wireless interface, such as a Bluetooth interface, for communicating with one or more external digital devices, such as smartphones .
• a wireless interface such as a Bluetooth interface
• an external device such as a laptop computer or smartphone, may be programmed with an application to remotely send and receive data and/or control signals with the control unit 211 in order to control the operation of the system 200 by, for example, adjusting the operation parameters of anodic potential, air flow, and/or water flow.
• the outer shell 202 may be made of any suitable material, such as plastic, and may have any suitable form factor and size. For example, it may be a compact,
• cylindrical container that may be easily carried by a person.
• Each of the stages may be self-contained in
• Figure 7 shows an example of a self-contained shell for the ECR 206.
• the three stages may be re-ordered relative to each other; or the internal components may be located at different places within the shell 202 other than the ones shown in Figure 6. Additionally, one or more of the components 204-214 may be located externally outside the outer shell 202.
• FIG 7 is an exploded perspective view of an exemplary ECR module 206 included in the modular system 200 shown in Figure 6.
• the ECR module 206 includes an outer shell have two mated shell halves 250, 252 configured to enclose the other components of the module 206.
• the top shell half 250 includes an inlet 254 for admitting water into the module 206, and the bottom shell half 252 includes an outlet 256 for releasing water that has passed through the ECR module 206.
• anode 258 Contained within the outer shell are an anode 258 having a plurality of holes 260 formed therein for passing water, a non-conductive spacer 264, a cathode including a puck 262 of porous carbon material and a conductor 266 in
• the top and bottom shell halves 250, 252 may be made of any suitable plastic or other material.
• the shell halves 250, 252 may have mated threads so that the shell halves 250, 252 can be screwed together to form a water tight seal.
• the internal gasket 270 is provided to prevent leakage from the module 206 at the joint between the shell halves 250, 252.
• the anode 258 may include any of the anode
• the cathode may include any of the cathode
• Figures 8a-c are graphs showing experimental results for cyclic voltammetry (CV) curves for an example disclosed electrode, namely, a PCM-HDA cathode.
• CV curves are shown for a PCM-HDA cathode in Ar (dash line) or 0 2 (solid line)
• PCM 52 exhibits excellent electrocatalytic behavior of oxygen reduction.
• the peak potential of PCM-DAH for oxygen reduction is -0.51 V, -0.57 V, and -0.63 V for pH 4, 7, and 10, respectively. This is similar to those measured for PCM-EDA, PCM-TMA, PCM-TEA, and PCM-KOH .
• PCM-HDA presents the highest peak current density.
• FIG. 9 is a graph showing experimental results of
• PCM-KOH (PCM-KOH) .
• the advantage of the unique pore structure within the PCM-HDA is clearly demonstrated.
• Figures lOa-f are graphs showing experimental results of pharmaceutical removal during continuous wastewater treatment using an example disclosed porous carbon electrode, namely a PCM-HDA cathode, in an electro-peroxone system. The testing was performed using stage 2 (an example flow-through ECR 206) of the system 200 shown in Figure 6.
• Figure 10a shows the experimental results for propranolol removal
• Figure 10b shows the experimental results for carbamazepine removal
• Figure 10c shows the experimental results for trimethoprim removal
• Figure lOd shows the experimental results for ranitidine removal
• Figure lOe shows the experimental results for cimetidine removal
• Figure lOf shows the experimental results for ciprofloxacin removal.
• the figures show the treatment efficiency of using the PCM-HDA ECR to treat relatively high concentrations (800 nMol) of pharmaceuticals.
• the y-axis of each graph represents the ratio (C/C 0 ) of a presently measured concentration of the contaminant (C) to the starting concentration of the contaminant (C 0 ) .
• Figure 11 is a graph comparing the experimental results of contaminant removal using an example disclosed porous carbon electrode (i.e., an example PCM-HDA cathode) and other known water purification techniques during continuous water treatment.
• the graph compares test results for an ozone process, electrolysis process, electro-peroxone (e-peroxone) process using conventional carbon bonded (CB) material as a cathode, and an e-peroxone process using a PCM-HDA cathode (HPC) .
• the test results show that the disclosed PCM-HDA cathode performed significantly better than known systems.
• Figure 12 is a graph showing experimental results of desalination using one or more disclosed porous carbon
• PCM-HDA electrodes for example, a pair of PCM-HDA electrodes.
• Any of the reactor systems disclosed herein can be modified to perform desalination. In general, the desalination process is based on capacitive deionization (CDI) .
• CDI capacitive deionization
• PCM electrodes are used as both the cathode and anode in the disclosed systems, a PCM electrode substituting for a metallic anode. The Na + and CI " is electrosorbed onto the PCM
• regeneration of the system after a period of time may be performed to flush Na and CI from the PCM electrodes. Because Na + and CI " are electrosorbed onto the carbon monolith material, over time, adsorption equalibrium will be reached and therefore desalination
• the regeneration is achieved by temporarily switching the voltage polarity of PCM electrodes, i.e., the original cathode becomes the anode and the original anode becomes the cathode, so the electrosorbed Na + and CI " will be desorbed and flushed away, allowing desalination to proceed. Also, for desalination, no air/ozone is required, and thus, no ozone generator and air pump are necessary.
• electrode system is capable of continuously removing about 10 ppm of NaCl (as shown in the graph between about 3 to 7 minutes and 15 to 20 minutes, which is roughly the
• brackish water 0.5-30 ppm NaCl
• a breakthrough in the electrosorbsion of Na + and CI " occurs between about 9 and 13 minutes of operation, as shown in the graph by the peaking of NaCl concentration in the water.
• a regeneration cycle occurs, causing the removal efficiency to be restored, as shown at the period of 15 to 20 minutes in the graph.
• test conditions were a flow rate of lOmL/minute, a potential of 6 volts being applied between the electrodes during desalination, and a potential of -6 volts being applied between the electrodes during desalination.
• the starting concentration of NaCl in the water was 100 ppm.
• the disclosed electrochemical reactor may be employed in solar powered toilets and waste treatment systems, for example, those disclosed in U.S. Published Patent
• the voltage source 18 of Figure 1 or power supply 216 of Figure 6 herein may be a photovoltaic source, and the electrochemical processing can be done on human waste.

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• 2018
  • 2018-02-09 US US15/892,923 patent/US20180222781A1/en active Pending
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